Rearing performance of tropical Tasar silkworm (Antheraea mylitta Drury) on Cashew (Anacardium occidentale L.) and its commercial silk properties

Tasar silkworm, Antheraeamylitta Drury (Lepidoptera: Saturniidae) is one of the commercially exploited non-mulberry silkworms mainly reared outdoor on many wild plants. The ecorace of tasar silkworm occurring in cashew (Anacardiumoccidentale L.) plantations of Puttur was identified as A. mylitta KE-02. Pooled egg, larval and pupal period of tasar silkworm upon indoor rearing on cashew recorded were 6.43, 28.69 and 25.36 days, respec-tively, with the effective rate of rearing of 40 %. The average cocoon weight, pupal weight and shell weight recorded were 6.24 g, 5.30 and 1.18 g, respectively. The high shell ratio of 22.26 %, shows a healthy trend for high yielding tasar rearing on cashew. The commercial silk properties of cashew reared cocoons were assessed in comparison to silk properties of cocoons reared on Terminalia paniculata. Average filament length, average non-breakable filament length, denier, strength and elongation were found 547.2 m, 1231.6 m, 8.92 D, 1.57 gpd and 16.9 %, respectively on cashew and 518.2 m, 161.94 m, 9.13 D, 1.73 gpd and 18.7 % , respectively on T. paniculata. The present study has documented the biology of tasar silk worm on cashew and also the commercial silk properties of cocoon reared on cashew at preliminary level.

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Controlling of bacterial and fungal diseases that contaminating mulberry silkworm, Bombyx mori by using some plant extracts

Bulletin of the National Research Centre ◽

10.1186/s42269-019-0218-3 ◽

2019 ◽

Vol 43 (1) ◽

Author(s):

Mahmoud S. I. Saad ◽

Enas M. Y. Elyamani ◽

Walaa M. M. Helaly

Keyword(s):

Bombyx Mori ◽

Larval Mortality ◽

Pupal Weight ◽

Filament Length ◽

Larval Weight ◽

Shell Weight ◽

Cocoon Production ◽

Black Seed ◽

Mulberry Silkworm ◽

Silk Filament

Abstract Background Mulberry silkworm, Bombyx mori L. is one of the most economically important insect because its production of silk which interfere with many important industries. Diseases of the silkworm, B. mori such as viral, bacterial, fungal and protozoan pathogens seriously affect their cocoon production. Bacterial and fungal pathogens independently cause the highest cocoon loss, so the use of botanicals is considered an important strategy to control diseases of silkworm. Results The artificially infected silkworm, B. mori larvae with Bacillus thuriengiensis when treated with concentrations of 2 and 3% of black seed and basil leaves extracts increased significantly larval weight and decreased larval mortality. In addition, 3% basil leaves extract and 1% of black seed increased pupal weight. Cocoon weight and cocoon shell weight increased significantly by 3% basil leaves extract treatment. All tested concentrations of black seed extract increased the silk ratios of the resulted cocoons as compared to the infected control. For technological parameters, all tested extracts at 3% concentration caused the highest silk filament length; meanwhile control larvae recorded the highest silk filament weight and size. Regarding the mulberry silkworm, B. mori artificially infested with conidial solution of Beauveria bassiana when treated with all concentrations of the tested plants showed an enhancement in larval weight, pupal weight, cocoon weight, cocoon shell weight, silk filament length, and filament weight and reduced the larval mortality percentage. The highest silk filament size were recorded for the control group. Conclusions Tested concentrations of Morus alba, Ocimum basilicum leaves extracts and Nigella sativa seeds extract have suppressed the bacterial and fungal disease spread when used three times through both 4th and 5th larval instars. Moreover, the biological characters and technological traits enhanced by using of these extracts, so it can be used in sericulture for improving cocoon crop quality and quantity.

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